Open the Home + Security app and select “Install new products” in the settings. Follow the instructions. Make sure your smartphone is connected to a 2.4 GHz network. The EOS 300 class does not support 5 GHz networks. If you are using an iOS device and you are getting the “Unable to add accessory” error, put your iOS device in airplane mode for more than 30 seconds, turn off airplane mode, and then restart the installation. If you are using an Android device, make sure that no ad blocking apps are enabled on your device. If so, please disable the ad blocking application when installing the Class 300 EOS. If you want to install the Class 300 EOS on a Wi-Fi repeater: Make sure it does not have the same name (SSID) as the router. To check if the repeater is working properly, try installing the Class 300D directly on the router (by changing the network the smartphone is connected to as well).